1. Field of the Invention
The present invention relates to cane harvesting equipment and more particularly to an improved chopper harvester having rotary knives for cutting cane whole stalks into short pieces or "billets", wherein the knives rotate with a flywheel and clutching apparatus that is environmentally sealed and easily adjustable after quick visual inspection of the clutch assembly.
2. General Background
Sugar cane harvesters are large powered, mobile machines that can harvest one or two rows of standing cane while advancing quickly through the cane. Sugar cane is a very substantial crop to harvest. Sugar cane stalks generally stand between about five and eighteen feet (15;-18') high. The cane stalks are thick (about 1.5-2.0 inches in diameter) and carry bulky leafy material.
Many commercially available harvesters cut the cane at its base, and "top" the stalk by cutting off the upper leafy part of the stalk. The so called "wholestalk harvester" piles the cut cane in the field where it is picked up later with other equipment, loaders and cane carts.
Another type of cane harvester is called a chopper harvester. Chopper harvesters can also harvest one or two rows of sugar cane at a time. Chopper harvesters cut the cane at its base with a basecutter blade. They also slice the top off the cane stalks with a "topper". The remaining stalk is then chopped with hydraulically driven rotary knives into short pieces or "billets".
There are various types of mechanized sugar cane harvesters that harvest the growing cane stalks by cutting the cane at its base, and then transferring the cut cane to a receptacle vehicle such as a cane wagon or cane cart. In the process, leafy trash material is removed from the stalks so that the trash is not carried to the mill. A powered extractor fan is positioned in the upper portion of a cleaning chamber or housing and above a cane billet feed path. An air outlet above the fan directs the discharging air and leafy trash. "Chopper harvester" sugar cane harvesters cut the cane wholestalks into short pieces or billets after a "topper" removes the upper leafy part of the stalk.
Early harvester mechanisms were often attached to a tractor or towed. Examples of early harvesters can be seen in The Ashton U.S. Pat. No. 2,755,912 entitled "Harvesting Mechanism"; the Collins U.S. Pat. No. 2,835,298 entitled "Rotary Cutting Mechanism", the Gaunt et al. U.S. Pat. No. 3,141,281 entitled "Machines For Harvesting Tall Row Crops".
In the Gaunt patent a tractor is shown with a harvesting machine attached to the side of the tractor and wherein rotating drums having knives thereon are used to cut the stalks into small pieces. The device is adapted for use with sugar cane as an example. The Kessler U.S. Pat. No. 3,377,785, the Johnston U.S. Pat. No. 3,397,520 and the Bunting U.S. Pat. No. 3,422,906 show other early harvesters.
A topper for use with the sugar cane harvester is the subject of U.S. Pat. No. 3,473,308 issued to Zagorski. A cutter, conveying rollers, and chopper drums are seen in a patent to Driller issued Dec. 9, 1969 entitled "Crop Harvester Material Distribution Apparatus", U.S. Pat. No. 3,482,690.
A sugar cane harvesting combine is shown in U.S. Pat. No. 3,599,404 which has a mobile chassis with a supporting framework and wheels, and adjustable cane top severing mechanisms consisting of a shielded disc with blades, and a hydraulic adjustment means with rods to direct the cane to the top cutting area, curved paddles to discharge the cane tops, and a stalk severing mechanism with oppositely rotating horizontal cutters on hydraulically controlled skids, and means of directing falling cane into the stalk cutting mechanism, with a series of conveying means to dispose of the cut cane.
The Mizzi U.S. Pat. No. 3,673,774 provides a sugar cane harvester that has cutters for removing cane tops and cutting the stalks which are conveyed to a chopper having a bladed and a slotted rotary interacting to cut the stalks into billets and deliver them to a cane cleaner of two parallel rotating drums which tear leaf from the billets and discharge them to an elevator, on which they are carried over parallel screws, alternate screws being oppositely wound and oppositely rotated, for pulling leafy matter from the billets before the billets are discharged on the elevator.
U.S. Pat. No. 3,848,399 entitled "Sugar Cane Harvesters" provides a harvester having twin contra-rotating base cutters feeding whole sticks to cane chopping apparatus which sub-divides the sticks. Each base cutter is in the form of a drum, open at one end and arranged with its open end facing downwards. Outwardly projecting blades are mounted at the open end of the drum. The blades are thereby downwardly offset from the closed end of the drum which reduces power consumption and causes less soil and sticks to be fed into the harvester with the cane sticks. The harvester has a plurality of conveying rollers and a pair of contra-rotating cane choppers that receive the cane from the rollers and chop it into billets. The contra-rotating choppers throw the billets into a primary elevator. As the billets fall into the top of the elevator onto the inlet of a secondary elevator they are subjected to an air blast from the blower to remove cane trash. The cane falls from the top end of the elevator into a trailer and is simultaneously subjected to an air current produced by a fan unit to remove any remaining trash.
The Quick U.S. Pat. No. 4,019,308 entitled "Base Cutting Apparatus For Sugar Cane Harvesters" shows a cane harvester having scrolls, base cutters, conveying rollers to convey cut cane upwardly and rearwardly through the harvester, a topper to cut the tops of cane stalks, contra-rotating drums having cutting knives thereon, and an extractor having a fan for removing trash.
Another Quick U.S. Pat. No. 4,121,778 provides an air intake for trash removal apparatus of a cane harvester. The air intake forms the lower portion of the housing of the trash removal apparatus and also serves to guide cane billets into the hopper of a pivotally mounted billet discharge conveyor. The air intake is formed as a deflectable air permeable curtain of perforated rubber sheeting which avoids both damage to the air intake and jamming of the conveyor during use. Another version of the air intake includes hanging chains through which air can pass.
The Canavan U.S. Pat. No. 4,295,325 entitled "Sugar Cane Harvester" provides a self-propelled harvester having a base cutter for cutting cane near the ground level, a chopping cutter for cutting the stalks into billets, a feed for feeding the stalks from the base cutter to the chopping cutter and means for elevating and discharging the billets, the chopping cutter and elevating means including a rotary cutter with a knife blade on a rotating shaft and a thrower having a vane extending from the thrower shaft, the two shafts being parallel and contra-rotated, the cutter knife blade and vane co-acting to sever cane fed into the chopping cutter into billets, the thrower vane acting to throw the severed billets upwardly through a cane guide chute from which they are discharged, preferably into a bin mounted on the main frame and capable of being tilted to empty its contents.
It is known in the art to chop sugar cane into short stalks or billets and to also cut leafy trash material. Early Massey Ferguson U.S. Pat. Nos. 3,788,048 and 3,830,046 relate to sugar cane chopper harvesters that cut the cane stalks with a base cutter and then convey the stalks rearwardly in the harvester using conveying rollers, one of the sets of conveying rollers being a set of chopping rollers in the form of two rotating drums, each having knife blades thereon. The chopping drums rotate and cut the cane stalk and its attached leafy material into pieces. Thereafter, the cane billets or pieces fall into a hopper or receptacle, and the leafy trash material is separated from the crop with an extractor or cleaning chamber. U.S. Pat. Nos. 3,788,048 and 3,830,046 are hereby incorporated herein by reference.
There have been various attempts to improve the operation of sugar cane harvesters that use chopper knives including drum knife arrangements. Years ago Massey Ferguson manufactured and offered commercially a number of harvesters with base cutters to cut the cane stalks at their lower end or base, toppers to cut leafy material off the top of each cane stalk, conveying rollers to convey cane wholestalks rearwardly in the harvester, chopper rollers in the form of rotating drums having the cleaning chamber. The Massey Ferguson model 205 Sugar Cane Harvester is an example of such a prior art "chopper" type sugar cane harvester that is made generally in accord with the above discussed Massey Ferguson U.S. Pat. Nos. 3,788,078 and 3,830,046.
Austoft (formerly known as "Toft", "Versatile Toft", "Versatile Corporation" and "Toft Brothers") is an Australian company that has also manufactured and sold sugar cane harvesters that include a base cutter for cutting the cane stalks at the bottom, a topper for chopping the leafy material from the top of the cane stalks, conveying rollers for conveying cut cane stalks rearwardly in the machine, and a cutter for severing the cane stalks into a plurality of billets. Such "Austoft" or "Toft" models include 4000, 6000, 7000 and 7700 harvesters.
In the Versatile Corporation U.S. Pat. No. 4,555,896, issued to Stiff et al., there is provided a sugar cane harvester in which chopped crop is conveyed from a chopping mechanism to a cleaning mechanism.
The assignee of the present application, Cameco Industries, Inc., has sold "chopper" sugar cane harvesters under the model numbers 1000, CH2500 CHT2500 and CHW2500. U.S. Pat. No. 5,092,110 assigned to Cameco relates to a Primary Extractor Apparatus that has been used on the Cameco model CH2500 harvesters. CH2500 series harvesters have been on sale since about 1990.
One of the problems facing the billet or chopper type harvester is that of efficiently chopping cane wholestalks into pieces. These stalks carry much unwanted vegetation, primarily leafy matter. They also carry dirt, mud and/or small pebbles. This combination creates terrible wear problems for the machinery that is a part of the cane stalk chopping mechanism that creates the desirable "billets" of cane.
Another problem that plaques chopper harvesters is vibration. The knives that cut large stalks of cane into short pieces generate a terrific amount of stress and vibration. This vibratory force can loosen mechanical parts.
One such part that is subjected to all of these environmental problems is the clutch apparatus that works in concert with the chopping blades, the rotating blade drive shafts, and the associated flywheel. The flywheel has a tensioning or clutch mechanism. A farmer must properly adjust the tensioning or clutch mechanism if the machine is to operate properly and avoid undue wear.
In summary, the clutch portion of the rotary knife drive mechanism on chopper type sugar cane harvesters is subject to water (because of weather and washdown), dirt, mud, pebbles and vibration.